Drilling



March 22, 1960 H. STRATTON 2,929,610

DRILLING Filed Dec. 27, 1954 s Sheets-Sheet 1 FIG.

"m W a A IN V EN TOR. HAL STRATTON MMeM A TTORNEYS March 22, 19 60 H.STRATTON DRILLING 5 Sheets-Sheet 2 Filed Dec. 27. 1954 FIG 2.

P 40 l I INVENTOR. HAL STRATTO/V Vii H III March 22, 1960 H. STRATTON2,929,510

DRILLING Filed Dec. 27, 1954 5 Sheets-Sheet 3 FIG. 3.

Rx 121M525. HAL STRATTON WJZJAMM A 7' TORNE KS H. STRATTON DRILLINGMarch 22,1960

Filed D90. 27, 1954 FIG. 4.

5 Sheets-Sheet 4 INVENTOR. HAL STRATTON March 22, 1960 H. STRATTONDRILLING 5 Sheets-Sheet 5 Filed Dec. 27. 1954 INVENTOR. HAL .STRATTONATTORNEYS DRILLING Hal Stratton, La Habra, Calif., assignor to Shell OilCompany, Continental Oil Company, both of Los Angeles, Calif., bothcorporations of Delaware, The Superior Oil Company and Union Oil Companyof Caiilornia, both of Los Angeles, Calif., corporations of Californiaice Patented-Mar. 22, 1960 duit into the well. Thereafter the drillpipe, drill bit and underreamer are withdrawn up through the well con- 7ing the well to the required depth, the well conduit is ApplicationDecember 27, 1954, Serial No. 477,307

9 Claims. (Ci. 2551.S)

This invention relates to underwater drilling and more particularly tomethods for setting a casing or a well conduit in an underwater well.

At the present time underwater or off-shore well drilling isaccomplished from stationary structures rigidly anchored to theunderwater formation. These structures provide static bases for drillingequipment and are satisfactory for relatively shallow water, forexample, depths of 50 or less. However, for deeper water, for example,depths of several hundred feet, stationary structures are not alwayseconomically practical. Furthermore, the structures are sometimespermanent installations which may become navigation hazards. UnitedStates Patent 2,808,229 issued October 1, 1957 on application SerialNumber 468,214 filed November 12, 1954, describes in detail apparatusand methods for drilling underwater wells from a floating vessel toovercome the disadvantages of static structures. In that co-pendingapplication there is described a receiver assembly connected to theupper end of a well conduit projecting from an underwater well. Thereceiver assembly is used to guide drilling equipment from the floatingvessel into the well. This invention is concerned with methods andapparatus for positioning the well conduit or pipe and receiver assemblyin an underwater well.

One technique for accomplishing this objective is described inco-pending application Serial No. 481,529 filed January 13, 1955, andinvolves drilling the conduit into the formation by providing cuttingmeans on its lower end and rotating the conduit from the vessel much inthe nature of a regular drill string. Many formations, however, are ofsuch nature as to impair operations in this manner and to require moresophisticated drilling techniques for penetration. This invention solvesthis problem by the method of forming the well, or at least the upperportion of the well, in the formation with a drill pipe and thereafterworking the well conduit or pipe down into the well over the drill pipe.The word formation is used herein to mean the ground forming and beneaththe bottom of a water body.

Preferably, fluid is circulated out the lower end of the well conduit asit is lowered in the well to prevent drill cuttings from being forced upinto the well conduit.

in a presently preferred form, the well is drilled with a drill bit andunderreamer attached to the lower end of the drill pipe. After the wellhas been drilled to a depth slightly greater than the total length ofwell conduit to be positioned, the drill bit and underreamer are raisedslightly ofi the well bottom to avoid sticking of the drill pipeby anymaterial which may slough ofi the well Wall. With the drill pipe, drillbit and underreamer in the well, the well conduit is slipped down overthe drill pipe and into the well, the drill pipe serving to guide thewellconduit to leave the well conduit in the well.

In some situations, for example, where the well wall tends to sloughexcessively it is desirable to run the well conduit into the well as thewell is drilled. This invention also accomplishes this objective byproviding method whereby the well conduit is releasably held around thelower portion of the drill pipe as the well is drilled, and is carriedinto the well as drilling proceeds. Upon drill released and the drillpipe is withdrawn.

In setting pipe in accordance with this invention drillingfiuid may becontinuously circulated. In conventional procedure drilling fluidcirculation is interrupted, i.e. discontinued while the well conduit islowered. This sometimes allows the drilling mud to lose its properphysical condition and makes resuming subsequent working in the welldifficult. Continuous circulation of the drilling fluid, when the wellconduit is set in accordance with this invention, avoids thisdifficulty.

These and other aspects of the invention will be more clearly understoodfrom the following detailed description taken in conjunction with theaccompanying drawings, in which:

Fig. 1 is a schematic elevation, partly broken away, showing theposition of the well conduit on the drill pipe after the well has beendrilled but before the well conduit has been lowered into the well;

Fig. 2 is a schematic elevation, partly broken away, of the floatingvessel and associated drilling equipment of Fig. 1 illustrating theposition of the well conduit on the drill pipe after the well conduithas been lowered into the well;

Fig. 3 is an elevation, partly in section, of the upper end of the wellconduit set in the well with a receiver assembly and a circulating headmounted thereon in sealed relationship;

Fig. 4 is a view taken on line 44 of Fig. 3;

4 Fig. 5 is a view taken on line 55 of Fig. 3;

Fig. 6 is a view taken on line 6-6 of Fig. 3;

Fig. 7 is a View taken on line 7-7 of Fig. 4;

Fig. 8 is a vertical section of an alternate arrangement of a wellconduit illustrating an alternate method for positioning the wellconduit in a well;

8 Fig.1 9 is an enlarged view taken on line 9-9 of Fig.

Fig. 10 is a vertical section of a modified form of the apparatus shownin Figs. 8 and 9.

Referring to Fig. 1, a floating vessel 10, such as a ship, is anchoredby means of anchor lines 11, in a body of water over a formation 12 inwhich a well 13 is to be drilled. A drawworks 14 and power unit 15 whichmay be of conventional type, are mounted on the ship to operate ahoisting cable 16 carried over a crown block 17 located at the upper endof a drilling rig 18 erected on the deck of the ship. The traveling endof the hoisting cable carries a traveling block 19 and a hook 20 whichsupports a swivel joint 21. A Kelly joint 22 with a conventional Kellyvalve 23, extends downwardly from the swivel through a Kelly bushing 24in the center of a.v rotary table 25 mounted on gimbals in a manner suchas described in U.S. Patent 2,606,003. The rotary table is supported bya platform 26 directly over a cellar 27 which may be located in thecenter of a ship as illustrated. Power is supplied to the rotary tablethrough a shaft 28- tut ed b a ro ary ta le power unit 29 waste a 1 a Apressure circulating head 30 is releasably sealed to a receiver assembly31 attached to the upper end ofa well conduit 32 hanging verticallybeneath the cellar from a pair of guide lines 33 temporarily secured, at33A to the cellar Wall. A string of drill pipe 34 is connected to'thelower end of the Kelly and extends downthrough the cellarycirculating.head, well conduit, and into the.

well. A drill bit 35, underreamer 36, and drill collars re, Q sdts Q hew nd of h 'd l r e l epressurec cul a asi remnants.eases in det ailbelow, between thefrdtatable,drill pipe and the. l 9 6 80 a when, the .9ll il. ..t 1 in h W l 4% haun i i a d ll lsefi tlz 9r d 3 a be s m latedfiqm mi d teak. rj t 3 t i b a man al as. hwi h a inll ssf n'usi 1 .9 41t he wi l t-(n h s cen al fl sw f 9W K9 2 d il p p and dr l ll r b we.ta P e asalaa a e'bs nen the r l Pi e nd thewell wall, out, the;circulating head, andupa flexible. drilling mud'return; hoseldz exendingffrom the. circulat inghead to, the mudipi tf H I r IThejrieceiven3; includes an upright sleeve 5 6 (see. Fig.

3.) disposed co axiallyt about the upper portion of thewell conduit; Thesleeve is rigidly attached to the conduit,

for'example, by welding. A pair of diametrically opposed and radiallyextending guidejpost arms 58 are rigidly 9 tb-flwhfifinil fi a le e n eien l the guide vpost arms are If beams mounted. with the V flanges ofthe horizontal. V A separate. upright cylindrical and hollow guidepost59iswelded in amatching notchfiormednat the outer end of each. guidepost Eaclrguide post extends from the bottombi its respective arm to asubstantial distance above the A solid plug 60. is welded in the upperendof each guide post so that each plug is flush'with the upperenclofits respective 'guide' post. A separate upright triangular plate 61.is 'welded'across the upper surfaces: qf eaqh plug and guide. post; andis providedwith a transverse bore 62. The lower ends of the twoguideline cablesare'separately .attachedftothe upper end of arespeetivefguide post by nieans'of a swivel 63 connected to a shackle6jlwhich is attache alto its respective guide pos t through thebore.

A pair of opposed elongated SHPROITHI'IIIQS, 69 are at- .tached' to thesleeve "56 un de r the: guide post and extend outwardly a substantialdistance from the well. The

7 ,each other, e.g., by welding, after the well conduit is suspended inthe position shown inFig. 1."Thi' ee externalaligning lugs 72B arewelded at 120 intervals to the upper end of the well conduit below, andangularly displacedfrom the guide and landing plates (see Fig. 5). Thecir'culating head 30 comprises a frusto-conical shell 73 (see Fig.*3)"with its upper end connected-to a'well conduit seal housing 74, havingan uprightjcylindrical wall 75. The lower end of an annular flexiblewell conduit seal 76 is friction fitted into an upwardly opening annularchannel ,77 formed in thelower end of the well conduit sealhousingbetvvecn an upwardly extending ring n men an'anriular bottomIosiirflfiA forithefhbus'ihg the housing Wall. The uppe 'nd'o'f tliewell'condiiit seal' is fritibu'fittedinto down A ardly opeiiingafinillar channel 79 fdrmed in the upper end (if-th vvell conduit sealhousing between a downwardly extending ring '80 on an annular upperclosure 80A for the housing and the in the wall of the well conduit sealhousing so that hydraulic pressure may be applied by means of ahydraulic line (not shown) to the well conduit seal and force it to forma fluid-tight seal with the Well conduit. This also provides positivegripping means by which the circulating head is held down on the wellconduit during drilling operations. The lower end of a drilling mudconduit 82 is sealed into the upper end of th'e well conduit sealhousing. One'end of a drilling mud return nipple 83 is threaded throughthe drilling mud conduit wall. The other end of the nipple is connectedtothe flexible drilling mud return line 42 (see Fig. 1) which extends tothe mud pit 39 d in the vessel. r a

An aligning conduit 85 is co-axially disposed within the mud conduit sothat its lower'end terminates just above the upper end; of the wellconduit when thecirculating head is in the sealed position illustratedin Fig. 3. An outwardly extending flange 86 attachedto the-intermediateportion of the aligning conduit'is secured by means of b0lts'87 to amatching outwardly extending flange 88 provided on the upper end of themud conduit. The inside. diameter or the aligning conduit is smallerthan they inside diameter of the well {conduit and therefore serves toguide the drill bit into the well conduit and avoid catching of the biton the upper end of the well conduit as the bit is lowered into drillingposition.

1A drill pipe seal housing or body 90 having an outwardly turned flange;91 at its lower end issecur'ed to airqoutwardly turned flange 92 at theupper end of the aligning. conduit by means of bolts' 93.' externaldiameter of the body is less than that of thewellconduit seal housingand the body' external diameter is reduced at 94fjust above the'bodyflange. The body isprovided with a relatively large first internalbore.9. 5 extends from the upper end'of the body down near the portionof the ,housing'which is of reduced external diameter. The bore is thenstepped down to a smaller second boref96 for ashort distance, then isstepped down to athird bore 97 for a short distance, then is steppeddown to a fourth bore 98 for a short distance, then stepped up to afifth bore 99, slightly less than that of the third bore to extend to.

a point near the lower end of the body, and is then stepped up to alarger sixth bore. 100 which extends to the lower end of the body. v

A sleeve bearing 101, which may be lignurn vitae, for example, isdisposed within the large boret' at the upper end of the body, the lowerend of the bearing resting on the shoulder formed at the end of thefirst bore and its uppenend being flush with the upper end oi the body.The, inner diameter of the sleeye, bearing' is le ss,than that of thesecond bore. Theinner edgaer the'lower endof the annular sleeve bearingis beveled. at 102 to permitwater to'fiow up. through 5. lubricatinginlet port 1-93 provided in the horizontal sectionfof the body. wallabove the frediiced external diameter of thebo d y. A metal insert 104having an external diameter at its upper endlslightly lessthan theinternal diarnete rof the sleeve bearing is rotatably disposed withinthe sleeve bearing so that theupper end of the insert is below that oithefbeariug. An external spiral groove10'5 in the insert wall permitswater to be circulated byconvection and friction up from the lubricatinginlet port tokeepthe insert cool and lubricated during rotation. A V

Theexternal diameter of the insert 104 is stepped down to a reduceddiameter at the same-locationwhere the first bore ofthe body is steppeddown to a reduced diameter to form' an external shoulder 106 on'the,insert which restson a thrust'ring bearing 107 carried in the shoulderfor'medbetween the "third andfthehfourth bores, offthe body., Theupperend of the insert is ,internaliythreaded at 108 toreceive a.threaded bushing 109. which has.an annular external groove 110neanits-upper end and an outwardlysturned flange 1'11 which rests ontheupper edge of the insert.. An 0 ring 112 in the annular grooveeffects a fluid tight seal between the bushing and the insert.

The insert 104 is provided with a relatively large internal first bore113 at its upper end which tapers to a reduced second bore 114 near itsintermediate portion, then tapers again to a reduced third bore 115 inits lower portion, tapers again to a reduced fourth bore 116 and thensteps out to an increased fifth bore 117 to provide a lifting shoulder118 on which there is disposed a cushion ring 119 which may be made ofheavy rubber. An upper thrust ring bearing 120, which may be made ofMicarta (a phenolic plastic), is disposed on the upper end of thebushing and supports a retaining ring 121 provided with a pair ofdiametrically opposed slots 122 in its periphery, each slot beingadapted to receive a longitudinally movable locking pin 123. A fasteningring 124 is disposed on top of the upper end of the sleeve bearing andthe body wall and is rigidly attached to the body wall by means of bolts125. The inner periphery of the underside of the fastening ring isprovided with a groove 126 which communicates with an annular space 127formed between the upper thrust ring bearing, the upper end of thebushing, the fastening ring and the sleeve hearing. A plurality ofvertical lubricating outlet ports 128 in the fastening ring connect withthe groove 126 and permit the lubricating water to flow from theinterior of the body.

A pair of horizontal bores 129 through the fastening ring house thelocking pins. The bores are of reduced diameter at their outer ends toform a shoulder 130. A compression spring 131 is coaxially disposedaround each locking pin and bears against a flange 132 attached to theinner end of each locking pin and bears against the shoulder of thelocking pin bores. The outer ends of the locking pins extend out beyondthe fastening ring and are each provided with a transverse pin 133 whichholds a stop collar 134 around the outer end of each locking pin. A ringhandle 135 is welded to the outer end of each stop collar to facilitateits operation.

An annular flexible drill pipe seal 136 is coaxially disposed within theinsert and is supported at its upper end by a plurality of metal eyes137 molded into the seal and held by corresponding hooks 138 formedintegrally on a seal ring 139 secured to the underside of the bushing bymeans of bolts 140. The drill pipe seal has a relatively large firstbore 141 at its upper end and tapers to a reduced second bore 142 at itslower end, and is sufficiently flexible to be expandable to a largeenough diameter to permit the passage of drill pipe and drill collars.However, under ordinary drilling operations, the seal clamps tightlyaround the drill pipe or drill pipe joints so as to rotate with the pipeand effect a fluidtight seal.

An insert seal 143 is disposed in the annular space formed between thelower end of the insert 164 and the fifth internal bore 99 of the body.The insert seal is held up in position by means of an insert sealretaining ring 144 secured by means of bolts 145 to the shoulder formedbetween the fifth and sixth internal bores of the body.

.Referring to Fig. 3, an upper pair of diametrically opposed andradially extending guide brackets 147 (preferably short sections ofrelatively small I beams) are welded to the external surface of thedrilling mud conduit on the circulating head. A separate sleeve 148 inthe form of an upright, hollow, truncated, four-sided pyramid isattached to the outer end of each guide bracket by means of a pair ofvertical, spaced plates 148A which are welded at one end to the sleeveand arranged at the other end to fit on each side of the guide bracketsThe plates are attached to the guide bracket by means of bolts 14?. Aslot 150 (see Fig. 6) is provided in the sleeve wall between the twoplates and a respective guide line 33 is-slipped into each sleeve 148before the sleeve is bolted to the guide bracket -147.

A separate, outwardly extending plate- 151, curved'concave downwardly,is attached to the upper and outer edge of each guide sleeve to reducethe wear on the guide lines as the circulating head is raised andlowered.

A similar pair of lower guide brackets 152 are attached to the externalsurface of the aligning funnel 73 at the lower portion of thecirculating head. A separate guide sleeve 153 is attached to the outerend of each lower guide bracket, the principal difference from the uppersleeves 148 being that the curved plate is omitted. The guide sleevesare adapted to slip on and off the guide post and accurately align thecirculating head on the receiver assembly.

The well conduit 32 is positioned in the well by the method illustratedin Fig. 1 through Fig. 7 as follows:

rior to the lowering of the drill string or pipe 34, the well conduitand the supporting receiver assembly 31 are hoisted over the side of theship by a conventional ring (not shown). The external guide and landingplates 72A on the well conduit are welded to the internal guide lugs 72in the receiver assembly sleeve 56. The well conduit and receiverassembly are then lowered in the water beneath the keel of the ship andmaneuvered into an upright position to be supported by the guide cablesThe rotatable insert 104 the drill pipe seal housing is removed and thedrill bit 35, underreamer 36, drill collars 37, and drill pipe 34 arecoupled together and lowered through the circulating head 30, receiverassembly 31 and well conduit 32 until the bit nears the ocean bottom.The rotatable insert 104 is then slipped on over the upper end of thedrill pipe and locked into the drill pipe seal housing 90 by the lockingpins 123. The Kelly joint 22 is then coupled to the upper end of thedrill pipe and the drill bit is rotated by power supplied to the rotarytable 25. Drilling fluid or sea water is pumped down the drill string towash cuttings out of the well as drilling proceeds. The well is drilledto a depth equal to the length of the well conduit plus an additionalamount to allow for sloughing of formation from the wall of the well.After the required depth is reached, rotation of the drill pipe isstopped and the drill pipe is raised slightly off the bottom of the wellas shown in Fig. 1. Hydraulic pressure is applied to the well conduitseal 76 so that the circulating head is sealed to the well conduit 32.The guide lines 33 are then lowered to allow the well conduit to slidedown over the drill pipe and into the well, as shown in Fig. 2. With theKelly valve 23 closed, drilling fluid or sea water is pumped into thedrilling mud return line (which is temporarily connected to the pumpdischarge) and out the lower end of the well conduit 32 as it is loweredto prevent drill cuttings from being forced up into the well conduit andpossibly sticking the drill pipe 33 to the well conduit 32. The weightof the well conduit and circulating head is suflicient to overcome thefriction between the drill pipe and the drill pipe seal 136. The wellconduit may then either be cemented or held in the position shown inFig. 2 until the formation has had suflicient time to settle around thewell conduit and anchor it firmly in place.

Pressure is then released from the well conduit seal housing 76 and thedrill pipe, underreamer and drill bit are raised. The drill bit engagesthe internal cushion ring 119 in the drill pipe seal housing 90 andraises the circulating head 30 to the dotted line position shown in Fig.2. One of the guide lines extends forward under the keel of the vessel,over a supporting pulley carried by a forward bridle 161 slung under theforward part of the vessel. A weight 162 is attached to the free end ofthe guide line and hangs in the water-to maintain a constant tension onthe guide line. A similar weight 153 is hung on the freeend of the othercable which extends rearwardly under the keel of the vessel and is runthrough a supporting pulley 164 carried by a rear bridle Ids-slung underthe rear portion of the vessel.

33 directly under the cellar.

' duit.

The drill bit and underrean es combination may then be replacedhy aconventignaldrill bit and drilling may the be Q T T B.. l o. the eq red,dept as described in ctr-pe d n apn i t o i Serial Num e 8,214, filed.

' N mber; 1 .5

' I si d dur n he dr l ng o t e e l p o to ti he llccad 21a ea ng. uni sm ar to that of. thev well conduit seal76 can be usedto replace thedrill pipe Seal 136 or'be mounted jonthe upperend of the drill pipe sealto provide means for gripping the drill pipe 34 with adjustablepressure, This type, of arrangement has the advantage of rigidlyholdingand aligninglthe circulating head 35), receiver assembly 31. and wellconduit 32 around the drillpipe as the well conduit is lowered into thewell: Figs, 8 and 9 -illust rate;an alternate method for positioningawell conduit; 179 in an, underwater well 171. The upper portion ofthewellconduit is rotatably disposed through a sleeve 172; and the-upperend of the well conduitextends abovethe sleeve.v A pair of; opposed andoutwardly-extendingguide. post arms 173 are attached to the sleeve.Aseparatmiupright guide post 174 is attached to the outer end ofeachguidepost arm. The lower end ofe'acb guide post projects downwardly andoutwardly .past its respective guide 'arm to form an anchoring spike175; A separate, upwardly extending guide line176-is attached to the,upper end of each guide post.

An, annular lower bearing race 177' is attached to the the lower end ofadrill pipe 181 which extendsto. the

surface of the. waterto be powered by the drilling rig on V the floatingvessel asdescribed for; the arrangement in Figs, 1 through 6. A;plurality of. conventional holddown anchors 18-2, e.g. ofthe Guibersontype, are provided in the portion, of the drill pipe Within thewell'conduit, An anchor of this type is, illustrated in the CompositeCatalog of ;O il Field and- Pipe Line Equipment, twentieth edition, 1954,-55,, ,page 1940. -A plurality of laterally displaceable plugs 183in; each hold-down anchor are actuatedby the hydraulic pressure of thedrilling fluid within thedrill pipe and are iorced out against theinterior of the well conduit to the drill pipe, An in erted swab cup lfii is provided around the drill pipe near the lowerend ofthewellconduit,to seal the annular space between the. drill} pipe and; the wellconduit, Thus the fluid pumped out ofithe drill bit is forced to returnup the annularspace between the well conduit and the wellwall; toavoidthe possibility of'drill cutting s being c rried nt th qndu t ternrand k n the drill pipe Within the wellconduin The well is drilled andthe well conduit 1 70v positioned hin t e llls multaae uslv s fo w T e dl p p .14 r tatedb the dr ll a; g, ausi g e dn'llrbit and underrearner186 t'o -drill a well. The hold-down anchors ili cause thewell conduittqrotate and move down with the drill-pipe During the rotation of thedrill pipe, the; guide lines 176, extend upwardly and outwardly and areheld. in; aspread-position to avoid fouling with the drill pipeas-itisrotated; This ,aids the anchoring spikes 1751:- preventrotation of;the guide post arms as the well is drilled; After the. requiredwelldepth-is reached, the hydraulic pressure within the drill pipeisreleased, thus releasing-the hold-downi-anchors 182 from the wellcon-'The retractable blades 185 .on the underreamer alsomove in; when.thehydraulic pressure is, released.

shown; in'dottedlines in I V, A V

Underreamers: of this type-,areawellrknown in the; drilling industry, asfor example Baker model DT rotary hydran 1ic expansion wall scraperdescribed, in the Composite Catalog of Oil Field and, Pipe LineEquipment, twentieth l edition, 195455, pages 5235527 The well conduit170 may: be cemented in place or'the formation may be ale lowed tosettle around the well conduit.

i be modified so the well conduit is rigidly connected to the sleeveguide, post arms 173 and guide posts174, the rotational feature beingomitted, and the well conduit set in a. manner similar to that describedin Figs. 8 and 9. Even with the anchors 175. in the groundand the wellconduit rigidly connected to the: guide, post arms, the as.- sembly willrotate because the first few feet of ocean bottom is generallyrelatively soft. The casing is carried: downwardly with the drill pipe,until the anchors are in the ground firm enough toprevent furtherrotation, thus, establishing a firm footing for the upper end oi thewell conduit. With such an arrangement theguide lines 176; aretemporarily secured to the dirll pipe (or to the 'well conduit initiallyif the length of the conduit exceeds the water depth) above the waterlevel and are allowed to rotate with the drill pipe. The guide, lines.may be secured to the well conduit oridrill, pipe in several ways,

the simplestbeing merely totie the lines to the conduitv or drill pipewith a rope 188. As the Well is drilledand the CQnduit 170 and drillpipe181 move down, the guide lines if7dareintermittently disconnected andre-secured at a higher point to rotate with the drill pipe. 7 Thus, theguide lines rotate with the drill pipe and wellconduit, and donotbecometangled, as would happen if-their upper ends Were held in a fixedlocation on the floating vessel, The underreamer may also beomitted,thelower end of the well conduit being serratedasshown at 186 (Fig. 8)so that it aids the drill bit in cutting a well of diameter large enoughto accommodate the well conduit. After the well is drilled to theproper. depth, the well conduit may be anchored in place With cement187,or the formation may be allowed to settle around the well conduit. Theguide linesare'released from the drill pipe and secured to supportingpulleys as described for Fig. 2. The hold-down anchors 182 are releasedand the, drill pipe withdrawn from the well conduit 170.

I claim:

1; The method of setting pipe in a formation, underlying at body ofwater comprising locating a floating vessel overthe formation, anchoringthe vessel with elongated and laterally flexibleanchoring means intension to permit limited horizontal and vertical movement of the vesselby the elements while anchored; supporting a drill string from thevessel extending through the water to the formation and carryingdrilling means for forming a hole of larger diameter: thanthe.pipe,lowering the drill string from the vessel into contact with theformation, form ing in the formation with the drilling means a holelarger in diameter than the pipe, pumping fluid down through the drillstring to cause fluidto flow up the annulus between the drill stringandthe wall of the hole, suspending the.

pipe in tension around the drill string, lowering the pipe in the holeand affixing" at least aportion of theouter wall of the pipe: tothefOrmation while maintainingla flexible connection between, the:floating vessel ,and the pipein thesholejtolpermit:lateraldisplacementpf-thevessel; withlh'e. Pipe in,the-;h0le.. i

I 2,; Themethod according to claim lin which thefluid m nt ined latheholeswhilelqw ri g he :P PP is rillin mud. g V l 3. The method accordingto claim 1 which includes leaving the drill string in the hole while thepipe is further lowered, and'pumping fluid down the drill string tomaintain a flow of fluid up the annulus between the drill string and the,wall of the hole while the pipe is lowered. I I

4. The method of setting pipe in a formation underlying a body of watercomprising-locating a floating vessel over the formation, anchoring thevessel with elongated and laterally flexible anchoring means in tensionto permit limited horizontal and vertical movement of the vessel by theelements while anchored, supporting a drill string from the vesselextending through the water to the formation and carrying drilling meansfor forming a hole of larger diameter than the pipe, lowering the drillstring from the vessel into contact with the formation, forming in theformation with the drilling means a hole larger in diameter than thepipe, pumping fluid down through the drill string to cause fluid to flowup the annulus between the drill string and the wall of the hole,suspending the pipe in tension around the drill string, lowering thepipe in tension around the drill string while maintaining the drillstring in the hole, guiding the lower portion of the pipe into the holewith the drill string, further lowering the pipe into the hole whilemaintaining the hole substantially full of fluid to provide lubricationbetween the pipe and the wall of the hole while the pipe is beinglowered, limiting the downward movement of the pipe in the hole andaffixing at least a portion of the outer wall of the pipe to theformation while maintaining a flexible connection between the floatingvessel and the pipe in the hole to permit lateral displacement of thevessel with the pipe in the hole, thereafter advancing the drill stringthrough the pipe, and drilling additional hole with the drill stringbelow the lower end of the pipe.

5. The method according to claim 4 in which the pipe is anchored in thehole by pumping a fluidized cement into the annulus between the pipe andthe wall of the hole.

6. The method of setting pipe in a formation underlying a body of watercomprising locating a floating vessel over the formation, anchoring thevessel with elongated and laterally flexible anchoring means in tensionto permit limited horizontal and vertical movement of the vessel by theelements while anchored, suspending the pipe in tension beneath thevessel, supporting a drill string from the vessel extending throughthewater to the formation and carrying drilling means for forming a hole oflarger diameter than the pipe, lowering the drill string from the vesselthrough the suspended pipe into contact with the formation, forming inthe formation with the drilling means a hole larger in diameter than thepipe, pumping fluid down through the drill string to cause fluid to flowup the annulus between the drill string and the wall of the hole,lowering the pipe in tension around the drill string while maintainingthe drill string in the hole, guiding the lower portion of the pipe intothe hole with the drill string, further lowering the pipe into the holewhile maintaining the hole substantially full of fluid to providelubrication between the pipe and the wall of the hole while the pipe isbeing lowered, and limiting the downward movement of the pipe in thehole and aflixing at least a portion of the outer wall of the pipe tothe formation while maintaining a flexible connection between thefloating vessel and the pipe in the hole to permit lateral displacementof the vessel with the pipe in the hole.

7. The method of setting pipe in a formation underlying a body of watercomprising locating a floating vessel over the formation, anchoring thevessel with elongated and laterally flexible anchoring means in tensionto permit limited horizontal and vertical movement of the vessel by theelements while anchored, suspending the pipe in tension beneath thevessel with a flexible line, lowering a drill string from the vesselthrough the pipe angstahole larger in diameter than the pipe, pumpingfluid down through the drill string to cause fluid to flow up theannulus between the drill string and the, wall of the hole, lowering thepipe in tension around the drill string by paying out the flexible linewhile maintaining the drill string in the hole, guiding the lowerportion of the pipe into the hole with the drill string, furtherlowering the pipe into the hole while maintaining the hole substantiallyfull of fluid to provide lubrication between the pipe and the wall ofthe hole while the pipe is being lowered, and limiting the downwardmovement of the pipe in the hole and affixing at least a portion of theouter wall of the pipe to the formation, while maintaining the flexibleline between the floating vessel and the pipe in the hole topermitlateral displacement of the vessel with the pipe in the hole.

8. The method of setting pipe in a formation underlying a body of watercomprising locating a floating vessel over the formation, anchoring thevessel with elongated and laterally flexible anchoring means in tensionto permit limited horizontal and vertical movement of the vessel by theelements while anchored, suspending the pipe in tension from and beneaththe vessel, lowering a drill string from the vessel through the pipe tocontact the formation, the drill string carrying drilling means forforming a hole of larger diameter than the pipe, forming in theformation with the drilling means a hole larger in diameter than thepipe, pumping fluid down through the drill string to cause fluid to flowup the annulus between the drill string and the wall of the hole,suspending the pipe in tension around the drill string, lowering thepipe in tension around the drill string while maintaining the drillstring in the hole, guiding the lower portion of the pipe into the holewith the. drill string, further lowering the pipe into the hole whilemaintaining the hole substantially full of fluid to provide lubricationbe tween the pipe and the wall of the hole while the pipe is beinglowered, and limiting the downward movement of the pipe in the hole andaflixing at least a portion of the outer wall of the pipe to theformation while maintaining a flexible connection between the floatingvessel and the pipe in the hole to permit lateral displacement of thevessel with the pipe in the hole, said aflixing of at least a portion ofthe outer wall of the pipe to the formation being accomplished byplacing the lower end of the drill string adjacent the lower end of thepipe and pumping cement through the drill string to flow upwardly in theannulus between the pipe and the wall of the hole and allowing thecement to set.

9. The method of setting pipe in a formation underlying a body of watercomprising locating a floating vessel over the formation, anchoring thevessel with elongated and laterally flexible anchoring means in tensionto permit limited horizontal and vertical movement of the vessel by theelements while anchored, supporting a drill string from the vesselextending through the water to the formation and carrying drilling meansfor forming a hole of larger diameter than the pipe, lowering the drillstring from the vessel into contact with the formation, forming in theformation with the drilling means a hole larger in diameter than thepipe, pumping fluid down through the drill string to cause fluid to flowup the annulus between the drill string and the wall of the hole,suspending the pipe in tension around the drill string with the lowerend of the pipe spaced above the formation, lowering the pipe in tensionaround the drill string while maintaining the drill string in the hole,guiding the lower portion of the pipe into the hole with the drillstring, further lowering the pipe into the hole while maintaining thehole substantially full of fluid to provide lubrication between the pipeand the wall of the hole while the pipe is being lowered, and limitingthe down-

